Diabetes mellitus was known to ancient Indians as early as sixth century B. C. Charaka in his “Charaka Samhita” has mentioned the sweetness of urine in addition to polyuria. The Indian physician Susruta in 500 A.D described the disease as “Madhumeha” meaning rain of honey, (due to the phenomenon of attracting ants near the urine of a diabetic patient) with symptoms of foul breath, voracious appetite and languor. Other early Indian writings like Astanga-hrayda, Bhava-prakasa, Madhav-nidana etc. have also described diabetes. Globally, the number of people with diabetes is expected to rise from the current estimate of 150 millions to 220 millions in 2010 and 300 millions in 2025. The prevalence is increasing in the developing countries such as India, particularly in urban areas. The estimated number of diabetes patients in India was 19.4 million in 1995 and are expected to be 57.2 million in 2025 (W.H.O). In the United States, it is estimated that as of 2011, 25.8 million people (8.3% of the total population) were diabetic. About 2.15 lakhs of people under 20 years of age have diabetes (0.26% of all people in this age group). Approximately one in every 400-500 children and adolescents has Type-1 diabetes. In the age group of 20 years or older, 25.6 million (11.8% in men and 10.8% in women) have diabetes. In people above the age of 60 years, 10.9 million (26.9% of all people in this age group) have diabetes.
There are mainly two types of diabetes. Type-1 diabetes which was previously called insulin dependent diabetes mellitus (IDDM) or juvenile-onset diabetes. This develops when the body's immune system destroys pancreatic beta cells (β-cells), which are the only cells in the body that make the hormone insulin that regulates blood glucose level. Type-II diabetes was previously called non-insulin dependent diabetes mellitus (NIDDM) or adult onset diabetes. It usually begins as insulin resistance, a disorder in which the cells of the body fails to respond to insulin properly.
Unlike what was happening a few decades ago, anti-diabetic herbal formulations are marketed now in plenty in the form of powders, tablets, capsule and liquid preparations. Most of these have not undergone controlled clinical trials. Usually herbs with reputed anti-diabetic activity as documented in standard ayurvedic books or knowledge gained from experienced Ayurvedic practitioners are taken up and mixtures are prepared with arbitrary dosage. It is doubtful how some of these preparations are effective and what are the side effects, on long term usage are.
The medicinal plant Costus pictus D. Don is a very popular and fast-spreading ginger belonging to the family of Zingiberaceae that has been used as an ornamental climbing plant and is used as a munching dietary supplement for the treatment of diabetes in southern India. Costus pictus D. Don, commonly called as Spiral ginger, Stepladder or Insulin plant, belongs to the family Costaceae. The plant is cultivated as an ornamental plant in tropical gardens. It is a perennial herb growing up to 2-3 m and spreads 1.5-2 m. The glossy linear narrow leaves with characteristic wavy edges are arranged spirally on red coloured stem. The leaves are less fleshy and have an acrid taste. The inflorescences form both at the end of a leafy stem, and less often radically on a short nearly leafless stem. It can be recognized by its yellow flowers with red spots and stripes and appear in terminal cone. Propagation is carried out through stem cuttings and rhizome.
Different extracts of Costus pictus D. Don obtained from various parts of Costus pictus D. Don is reported to have different properties.
Costus pictus D. Don extracts have high concentration of oxalic acid. Since oxalic acid is found in high concentration in Costus pictus D. Don and found to be toxic, we standardized a method of making Costus pictus D. Don extract with very low level of oxalic acid content.
Oxalic acid is an organic compound with the formula H2C2O4. It is a colorless crystalline solid that dissolves in water to give colorless solutions. It is classified as a dicarboxylic acid.
Oxalic acid is reported to be toxic for oral administration (Merck Index, thirteenth edition, page 1237, para 6980: The European Agency for the evaluation of medicinal products veterinary medicines and inspections, Committee for veterinary medicinal products December 2003: Side effects of oxalic acid, Tracey Roizman D C, 2011).
Costus pictus D. Don extract (alcoholic, aqueous and juice extracts of leaves/whole plant) is reported to have anti diabetic property (U.S. Pat. No. 7,255,886, Merina Benny (2007); Nandhakumar Jothivel et al (2007): M A Jayasri et al (2008)).
Costus pictus D. Don is reported to contain oxalic acid (Camargo et al 0.2006; Moron et al. 2007). The leaves of Costus pictus D. Don are sour in taste due to the presence of high levels of oxalic acid in the leaves. (Rajendran Sathishraj et al, 2011).
Costus pictus D. Don extracts have high concentration of oxalic acid. If it is in small quantity it may not be that harmful and on the contrary may be beneficial against diabetes (Oxalic acid—Induced Modification of Postglycation Activity of Lysozyme and its Glycoforms (Hong Ying Gao et al, 2010). But Oxalic acid is known to produce Kidney stones. (Effect of dietary oxalate and calcium on urinary oxalate and risk of formation of calcium oxalate kidney stones, Linda K Massey, 1993).
In view of the above, we have developed a method of preparing an extract of Costus pictus D. Don having low oxalic acid and/or oxalates content and composition of Costus pictus D. Don extract having low oxalic acid and/or oxalates content. The disclosure not only provides a method of preparation of an extract of Costus pictus D. Don having low oxalic acid and/or oxalates content, but also a composition derived from therein. The constituents of the said extract of Costus pictus D. Don having low oxalic acid and/or oxalates content contain hydroxycinnamic acid derivatives and flavonol mono-, di- and triglycosides along with small amounts of free flavonols which is used for treating diabetes, dyslipidemia and related disorders.